Instagram users outraged over new rules made good on their threat to dump the popular photo-sharing app.

The app, which Facebook acquired for $1 billion earlier this year, may have shed nearly a quarter of its daily active users in the wake of the debacle, according to figures from AppData.

“[We are] pretty sure the decline in Instagram users was due to the terms of service announcement” on Dec. 17, AppData told The Post.

Instagram, which peaked at 16.4 million active daily users the week it rolled out its policy change, had fallen to 12.4 million as of yesterday, according to the data.

Last week, Instagram changed its terms of service to pave the way for advertising.

The new language would have allowed the company to sell user photos for advertising and promotions “without any compensation to you.”

The move sparked threats of a mass exodus, with celebrities including Kim Kardashian and Justin Bieber expressing outrage.

Just about the time the hashtag #boycottinstagram popped up on Twitter, Kevin Systrom, the CEO and co-founder, chalked it up to a big misunderstanding and insisted the company had no intention of selling users’ photos. Instagram has reverted to its old policy.

The damage, however, was done. While Instagram hasn’t said whether any of its 100 million subscribers deleted their accounts, the AppData figures show a steep drop in daily active usage.

It’s quite a comedown for the 2-year-old service, which bragged that it had its busiest 24 hours to date over Thanksgiving. That’s when users shared some 10 million photos — mostly of food.

There was no such announcement about Christmas, and yesterday Instagram declined to comment or provide any data for that day.

According to AppData, Instagram counted 14.5 million active users on Thanksgiving. By Christmas, that number had fallen to 12.5 million.

Instagram is still the second-most popular app and its monthly active users were rising, according to AppData.

(AppData isn’t able to measure every user of a particular app such as Instagram, but its numbers reflect trends in usage.)

Still, any hiccup in growth and daily activity could be detrimental as Instagram’s competition with services such as Twitter heats up.

Bieber withdrew his threat to leave, but as of yesterday Kardashian, the most followed user, hadn’t posted a picture of herself since the privacy flap.